Process of manufacturing- cyanamid



W. H. MIDDLETON. PROCESS OF MANUFACTURING CYANAMID.

APPLICATlON FILED MAY14.1919.

Patented Sept. 9, 1919.

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UNITED STATES PATENT OFFICE.

WILLIAM H. MIDDLETON, OF NIAGARA FALLS, ONTARIO, CANADA, ASSIGNOR TO AMERICAN OYANAMID COMPANY, OF NEW YORK, N. Y., A CORPORATION OF MAINE.

PROCESS OF MANUFACTURING CYANAMID.

Application filed May 14, 1919.

To all whom it may concern:

Be it known that I, \Viuaan H. MIDDLE- ron, a citizen of Canada, residing at Niagara Falls, in the Province of Ontario and Doniinion of Canada, have invented certain new and useful Iinprovmnents in Processes of lilanufacturing yananiid; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a process of producing calcium cyananiid and has for one of its objects to improve certain of the prior processes which have been heretofore proposed.

With this and. other objects in view the invention consists in the novel steps and combinations of steps coi'istituting the proc all as will be more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawings, forming a part of this specification in which like numerals designate like parts in all the views Figure l is a central vertical. sectional view of an a} )paratus suitable for carrying out the present l n'ocess; and

Fig. 2 is a fragmentary cross sectional view, taken on the line of Fig. 1.

In order that the recise nature of the invention maybe the more elearl y understood it is said ln the nninufacture of cyanamid under certain of the prior processes, it has been the practice. to fill a metal container with finely ground calcium ca-rbid and. to then place the said container together with its charge oi carbid in an oven lined with suit able refractory and heat insulating material. A suitable electrical resistor is inserted axially through the container. in a suitable space provided therefor, the lid is placed on the. oven, nitrogen is -'admitted and the current turned on to the resistor. At a tQJHIXJHlL-UIO upward 'of SO0-1000 C. the hot carbid adjacent to the resistor takes up nitrogen and converted into cyanamid. This reaction progresses throughout the Specification of Letters Patent.

Patented Sept. 9, 1919. Serial No. 297,071.

said containers becoming dented and battered through handling, making it difficult,

if not impossible to diseharge'the solid cake of cyanainid therefrom.

To obviate this difficulty and particularly during the War, when the cost of the metal containers became excessive, a substitute for the. same was sought and found, consisting in a paper sleeve which was inserted into the oven and thenfilled with car-bid, after which nitrification was started in the usual inanucr. This paper sleeve must be manufactured from stout paper and of definite dilIlPllSlODS and even with the greatest care, it would not infrequently tear or split from the pressure of the contained powdered carbid. Further, it was necessary that an annular space he left between. the paper and the oven for inserting the proper equipment for placing the paper and holding it in place during filling with carbid, as well as to assist in distribution of nitrogen, and this said space apprecial'il y reduced the capacity of a given sized oven and also increased the cost of equipment and housing.

In the present invention, 1 contemplate eliminating the metal container or the paper container entirely and in place of using these containers I propose to take the ordinary cyanamid oven, cylindrical in form and provided with the usual refractory lining, and line the same with a single sheet of corrugated paper, or preferably corrugated strawboard and to then insert the usual paper cylinder for forming" a space for the re. stor after which I can fill up the whole oven with cairbid.

The strawboai'd may be used in sheets without special forming, as they are merely laid around the inside wall of the oven with suitable lap: That is to say, prior to this invention, owing to the tendency of the very H1 1 cover 3 en the win I.

tense u e a theut it adhering t0 the resist l'hei; the enrme]? l I V lhe reels-lo ups-:11;

Owing); 10 ihe in l the lln'in B s l l G 1 11 IL 1 l on u 0 r tin nnple nine vet 'flll'l'O lt, n

hin n t 1b U nrenn t is however necesemfy a the een'lzei' around in the nlne'ful mwlmmxl have been able lve remeve the W1 :[n ll-us e (hetnbute the mtrogen by means of the broken up salrmw'hezuwl ust as 1'5 the oven itsel hid it;

smeot After ineer ll'JEE l van led eem'u le fl J1, ingel of e van meee emd 1:11

' 1 elii 1 th" l l {11TH en M were lined. as; described above, anal elf where the lining-s 2 are mere 01' less rough l (Julie nuns i il more 01 en Lneug J n l the n and lny 1t Ifl'en eenl n e 1e heel; eke es ehel'm'l a *hicl less dense masses, it has be those skilled H). the: all

per een m 'nf'e e epel. ent.

fin

e0 ill :er fold up a. nawew ell 21rd and held n V81 space is he the center of lhe o en m g e for th stance elf snch the eve the Whole ins ever Olll Whemxl bell m; lieml e115,

nelnleml my the 3 l lleyecl eased owinw center il" hewn, and l lfln-ltl 01' this corrugated be from above the nltrogen int 1 next 1 the 0v finely ground 0 the eerbicl in order lie provide m an speeleue pass-n th at a 00' curl nil nape? g," an

In it is not neces ex-able to use the corrugeted strewl; is pre' board hnlng' 10 of eerrnggn elclecl '0 en with :1 sheet nheve disclosed.

e 9 heen n1 w inelmle the ELF he m pee mine in l steps constituting the process, without departing :irom the spirit of the invention, and therefore I do not wish to be limited to the above disclosure except as may be required by the claims.

What I claim is 1. The process of producing cyanamid which consists in charging carbid directly inio'a suitable oven; providing a free space in said charge to accommodate a resistance element, placing against the inside oi said oven a material having an uneven surface to provide a multitude of additional tree spaces for the nitrogen in close proximity to the inside of said oven to facilitate the distribution of nitrogen through i said charge; introducing nitrogen into said spaces; and passing a current through said elcnn-nt whereby the temperature in said oven is raised to a point sutlicient to cause said nitrogen to react with said carbid, substantially as described.

2. The process of )l.'0(ll1t'lllg cyanamid which consists in lining the refractory walls of an oven with a combustible material having an uneven surl'ace; providing a sleeve of combustible material adapted to surround a heating element in said oven; charging the said oven with liuely divided carbid; proriding a conduit ol combustible material in said dialge adapted to facilitate the distribution of nitrogen therein; iidzroducing nitrogen into said conduit; and raising the temperature in said oven to a point sulli cient to consume said combustible material and to cause said nitrogen to react with said carbid, substantially as described.

3. The process of producing calcium cyan amid which consists in lining the refractory walls of an oven with corrugated strawboard material; inserting a tube of strawboard material in said even to provide an open space for a heating element; providing conduits of strawlmard material in said even to facilitate the distribution of nitrogen therein; charging the said oven with a calcium carbid; intrmlucing nitrogen into said oven; and suitably raising the temperature in said oven to a point where said strawboard material is charred and said nitrogen will react with said carbid to form cyanainid, substantially as described.

4. The process oi increasing the output ol. cyanamid. ovens which consists in lining said, ovens with corrugated sheet material pervious to nitrogen gas but impervious to iincly ground carbid to provide a multitudinous number of small passages tor, said gas; providing a passage for said gas in the body of said carbid; filling said even to its lined walls with a charge of cal-bid; introducing nitrogen into the charge and igniting the latter substantially as described.

In testimony whereof I allix my signature in presence of two witnesses.

Witnesses l iiomcncn V. lmnunan, liar l UNICUllrlll. 

